Characteristics of CO₂ Methanation of Catalytic Powder Layer on the Inner Surface of Circular Tube with Porous Structure

Abstract

CO₂ methanation is a technology that produce CH₄ using CO₂ and H₂ as raw materials through the Sabatier reaction. In the present study, the effects of temperature characteristics and CO₂ conversions in the two types of catalyst reactors (i.e., granular catalyst reactor, catalyst coated reactor) were evaluated. For the catalyst coated reactor, the base substrate was formed to a circular tube composed of agglomerates of metal particles by the Additive Manufacturing method. The catalyst layer was produced by the slurry coating method. The fine particles in the slurry were obtained by pulverizing the commercially catalyst with a hammer mill. The thickness of the catalytic particle layer was increased by multiple coating process, and the catalyst base-substrate was not exposed. The temperature rise of nearly 50°C occurred in the granular catalyst reactor at a set temperature of 300°C, while in the coated catalyst reactor the temperature was almost flat along the gas flow direction. Furthermore, it was clarified that the CO₂ conversions were determined by the maximum temperatures of the catalyst reactors. The proposed reactor in this study showed the possibility for solving the problem in the methanation process that is the temperature rises during the reaction.